This invention relates to a safety device for hypodermic needles and particularly a safety device that has increased protection measures to ensure that a contaminated hypodermic needle is securely enclosed by a needle sheath.
The prior art discloses a number of ways in which a hypodermic needle may be prevented from being exposed to the environment. One of these ways is to have a housing that may be pivoted from an open position whereby the needle is exposed to a closed position for enclosing the needle. References that disclose such pivotable housing include the following Hollister U.S. Pat. Nos. 4,982,842; 5,139,489; 5,154,285; 5,232,454; 5,232,455; 5,277,311; 5,423,765; 5,615,771; 5,649,622; 5,993,426 and Re37,110. All of the above noted Hollister U.S. patents are assigned to the same assignee as the instant invention and the respective disclosures of those patents are incorporated by reference herein.
For the prior art needle protection housings, particularly those with the Side Snap feature wherein coacting mechanisms at the base and the housing of the device coact to fixedly retain the housing to the base once the housing is pivoted to a position in alignment with the base, there is always the possibility that some person will deliberately remove the needle protection housing by prying the sidewalls of the housing so that the coacting mechanisms could no longer coact. This is possible due to the fact that the prior art devices are most likely made of plastic and therefore the needle sheath housing would have a built-in elasticity that allows a certain flexing of the sidewalls of the housing. This flexibility is required, on the one hand, to allow the coacting mechanism at the housing to snap over the corresponding coacting mechanism at the base for fixedly retaining the housing to the base. On the other hand, the same flexibility allows a person, if he is intent on sabotaging the integrity of the needle protection device, to pry the housing from the base by applying an extra amount of force, An illustration of the Side Snap feature is best shown in the aforenoted U.S. Pat. Nos. 5,615,771 and 5,649,622.
There is another shortcoming in the prior art needle protection devices. Such shortcoming results from the base, or the collar, of the device being snapped onto the hub or neck of the medical device. Such snap-on feature enables the safety device to rotate about the needle so as to enable the bevel of the needle to be oriented at a best position for use, relative to the needle housing. A device with such snap-on base or collar is best illustrated in the aforenoted U.S. Pat. Nos. 5,142,285 and 5,277,311. The disadvantage of such snap-on collar is the possibility, although unlikely, that a large enough force may be applied, accidentally or otherwise, to the collar of the device so that the device may be dislodged from the hypodermic needle during use.
Yet a further disadvantage of the prior art needle protection devices is that there is a lack of support for use when a patient is being pricked with a needle equipped with the safety device. Oftentimes, during the procedure of either injecting a patient or withdrawing fluid from the patient, particularly when the needle is to be intradermally inserted to the patient, there is a need to provide a support or anchor to stablilize the device as the needle is inserted to the patient. Currently, clinicians have to gauge by experience and instinct how best to stabilize a needle when performing an intradermal procedure on a patient.
To ensure that a needle protection device with a pivotable housing could not be sabotaged, two guard flaps, or arms are provided to the base of the device to act as barriers to prevent sections of the respective edges of the sidewalls of the housing from being exposed once the housing has been pivoted to be in alignment with the base of the device. In particular, the section of each sidewall of the housing coincides with the area of the housing whereat the locking mechanism for the housing is, and also the location of the coacting locking mechanism at the base, so that once the housing is pivoted to its alignment position and the respective locking mechanisms at the housing and the base coact to retain the housing to the base, it would be difficult for someone to deliberately remove the housing from the base by prying the sidewalls of the housing away from the base.
In a first embodiment, the guard flaps or arms are integrated to the base or collar of the device, and extend from the collar as flat pieces on opposite sides of the collar. The configuration of the guard flaps are such that it would enable a user to use those flaps as anchors or supports for stabilizing the medical device, and more particularly the needle, during a subcutaneous procedure by the user. After the procedure, the guard flaps act as partitions to close off the respective sections of the two sidewalls of the housing, once the housing is pivoted to the alignment position and the corresponding locking members or portions at the housing and collar matingly coact to retain the housing fixedly to the collar.
In a second embodiment, the guard flaps are configured to be curved arms that wrap around at least those sections of the sidewalls of the housing having the locking mechanisms once the housing is pivoted to its alignment position with the collar, to thereby provide even further enclosure for the appropriate sections of the sidewalls of the housing.
A variant of the instant invention safety needle device includes the integration to the housing a latching mechanism such as for example a hook that grasps the needle once the housing is pivoted to the position in alignment with the collar. The hook integral of the housing acts as a redundant safety feature to the Side Snap locking mechanism.
Another feature of the needle safety device of the present invention is the configuration of the base, or collar of the device. Specifically, the collar has an upper portion and a lower portion separated by an internal circumferential groove. The upper portion is an open-ended collar or ring whereas the lower portion is a closed ring. The internal circumferential groove that separates the two portions enables the collar to be fitted to the flange that extends from the base of the needle hub of a conventional hypodermic needle. The internal circumferential groove may be designed with respective tolerances to enable the collar, once fitted to the needle hub of the hypodermic needle, to either rotate about the needle, or stay fixed at a given orientation. If the collar were to stay fixed to the needle hub, it will stay fixed at a given angular orientation relative to the needle hub to position the bevel of the needle to a particular orientation relative to the housing, so as to provide the user with a clear view of the tip of the needle when inserting the needle to the patient. Once the collar is fitted to the needle hub of the hypodermic needle and the luer end of the medical device, be it a syringe or otherwise, the needle safety device is guaranteed to remain coupled to the needle hub insofar as the lower portion of the collar, which is closed, prevents the collar from being removed.
It is therefore an objective of the present invention to provide a needle safety device that has an anti-removal feature which prevents the deliberate removal of a needle protective housing to expose a contaminated needle.
It is yet another objective of the present invention to enable the needle safety device to be used as an anchor in a subcutaneous procedure with a patient.
It is yet another objective of the present invention to provide a needle safety device that, once fitted to the needle hub of a hypodermic needle, would remain fixedly coupled thereto once the luer end of a medical device is fitted to the needle hub of the hypodermic needle.